I mean I wouldn't call it bad writing that's for sure, cause I am guessing that this is at least 50 years later, as Judith mentions that she can't believe she actually broke the seal so she must have spent some time in the dungeon, so I am guessing that she couldn't travel to the surface anymore, and BEING LEFT ALONE with just your thoughts, nothing to do, no where to go, plain darkness, not following the normal human routine of eating, shitting, farting or anything at all, that would definitely fuck anyone up, like let's not forget how messed up Ageha is right now, and Kiska also said "I don't care anymore" I believe he would have given up on saving the hero completely, that's why he thanked her when she killed him, cause he wouldn't have picked going back by himself, at the same time Judith killing someone who hugs her out of nowhere after just telling her his name is super in character for her, honestly if anything this is a very realistic writing and very in character for everyone! I love it